This invention is related to application Ser. No. 642,276 filed Dec. l9, l975, now U.S. Pat. No. 4,034,973 by Kenneth A. Hams for an automated in-line mailing system. The disclosure in the Hams application is hereby incorporated herein by reference.
Briefly, the above-described disclosure of Kenneth A., Hams, with reference to FIG. 1 hereof, is for a mailing system 11 which receives a sheet web 13, and cuts it into individual sheets 15 with a cutter 17. The individual sheets 15 are registered against a registering wall 19 by a skewed endless conveyor 21 and fed to a buckle-folding machine 23. The folded sheets are then deposited with a collector, or catcher 25. It is this catcher 25 with which this invention is concerned.
As is described in the Hams' disclosure, the cutter 17 cuts a sufficient number of individual sheets 15 to compose a letter and then it ceases to cut and feed further sheets. The endless conveyor 21 and the buckle folding machine 23 operate continuously, feeding the cut sheets to the catcher 25. The catcher 25 collects the sheets of a letter in a stack and counts the sheets as it receives them. Once the catcher 25 has received a full letter, it ejects, or dumps, the stack onto an insert track 27 to be combined with additional inserts and stuffed into an envelope. When the catcher 25 ejects a pile of sheets, it provides a signal to the cutter 17 to begin cutting and delivering sheets again. As mentioned above, the Hams' disclosure is incorporated herein by reference to provide the details of the FIG. 1 system. It should be noted that the Hams' disclosure further describes a "two-up" system wherein the cutter 17 cuts dual, side-by-side, individual sheets and there are two, opposite registration walls 19, a folding machine 23 which can handle side-by-side sheets, and side-by-side catchers 25. In this system, when the cutter 17 finishes cutting a letter on either side of the side-by-side sheets, the cutter 17 discontinues cutting further sheets. Thereafter, when either of the catchers 25 ejects a stack of sheets onto the insert track 27, the cutter 17 is signalled to start cutting sheets again.
The prior-art catcher 25 which has been previously used in the Kenneth A. Hams system is depicted generally in FIG. 2. In this prior-art system, sheets are fed from the folding machine 23 (FIG. 1), by means of feed rollers 29 (FIG. 2), onto a feed plate 31 (FIG. 2) which includes driven endless conveyor belts 33. In this system, idler drop rollers 35 are mounted above the feed plate 31 and stop fingers 37 are positioned below the feed plate 31. The drop rollers 35 are mounted on levers 39 which pivot at an axis 41 upstream of the drop rollers 35 and the stop fingers 37, and the stop fingers 37 are mounted at a central hinge 43 of scissor levers 45 downstream of the drop rollers 35. The scissors levers 45 pivot on the drop roller levers 39 and a main frame at 47.
In operation of the prior-art device, when the catcher is set to accumulate a pile of sheets, the drop roller 35 is in an up position and the scissors levers 45 cooperate to hold the stop fingers 37 up in the path of sheets conveyed by the endless conveyor belts 33 on the feed plate 31. Thus, the sheets conveyed by the feed rollers 29 will form a stack or pile on the feed plate 31. When the catcher is moved to transport the sheets, the drop rollers 35 are moved downwardly, thereby urging the collected sheet stack against the conveyor belts 33 to forcefully drive it forwardly, and the stop fingers 37 are moved downwardly through the linkage of the scissor levers 45.
A difficulty with the prior-art catcher is that there can be very little clearance between the upper tip of the stop fingers 37 and the lower surface of the drop rollers 35 (1/8th of an inch in one embodiment) thereby limiting the size of the sheet stack. Of course the dimensions of the various levers could be modified, however, such a modification would create space problems and require either greater force or more movement from an actuator. In addition, the linkage formed by the many levers 39 and 45 are quite cumbersome, and this is particularly true in the "two up" system described above where it is necessary to have two catchers side-by-side. With regard to the two-up system, it is difficult to obtain access to the various levers when another catcher is directly adjacent to the levers of a catcher being examined.
Thus, it is an object of this invention to provide a catcher which allows the accumulation of various size piles, including piles of larger sizes than those allowed by the prior art system described above, but which does not take up an undue amount of space and which allows easy access linkages when used in a "two up" system with two catchers side-by-side.
Other prior art structures which relate to this invention include those disclosed in U.S. Pats. 3,263,992 to Schrempp, 3,637,203 to French, 3,724,640 to Rapparlie, and 3,844,552 to Bleau et al. All of these patents describe devices which interrupt the flow of sheets by bringing stop members into the paths of the sheets and thereafter moving the stop members out of the paths of the sheets and bringing driving rollers into contact with these sheets to drive them further. Schrempp, French, and Bleau et al. control the flow of individual sheets in this manner without stacking them. In Rapparlie, however, the holding stop, or abutment, causes conveyed sheets to stack behind the abutment. This system actuates the abutment when the stack reaches a predetermined height and a pressure roller urges a conveyor against the stack to transport it beyond the abutment. In this patent, the roller and the abutment are on a nonadjustable straight lever and have a fulcrum positioned intermediate the abutment and the roller. Both the roller and the abutment are positioned on the same side of the path of the sheets. The lever is pivoted to alternately bring the abutment into a blocking position and the roller into a driving position.
A difficulty with the Rapparlie system is that the length of the lever and the position of the fulcrum are rather critical and allow very little adjustment without affecting the amount of angular rotation required of the lever. That is, the lever must be unduly sort in order that the roller and abutment are not separated by an unduly large distance. In short, this system lacks flexibility and does not allow the elements of the abutment and roller to be adjusted to accomodate various size sheet piles.
Therefore, it is another object of this invention to provide a stop-and-roller system for a sheet catcher which can be adjusted to accomodate various size sheet piles and which does not have stops and rollers separated by an unduly large distance on one side of a sheet path.